Let-off mechanism for looms



(No Model.) 2 Sheets -Sheet 1.

A. D. EMERY.

I LET-OFF MEGHANISM FOR Looms, No. 503,468. Patented Aug. 15, 1893.

(No Model.) 2 Sheets-Sheet 2. A. D. EMERY.

LET-OFF MECHANISM FOR LOOMS.

N0. 503,468. Patented-Aug. 15, 1893.

'h 3 ewbdm UNITED STATES PATENT OFFICE.

ABRAM D. EMERY, OF TAUNTON, MASSACHUSETTS.

LET-OFF MECHANlSM FOR LOOMS.

SPECIFICATION forming part of Letters Patent No. 503,468, dated August15, 1893.

Application filed December 2, 1890. Renewed January 19,1892. Againrenewed December 1, 1892. Serial No. 453,695.

(N0 model.)

Looms, of which the following isa specification.

This invention relates to let off mechanism 1n which a worm gear isemployed to impart the unwinding motion to the warp roll, and

in which the motion to set a driving pawl, and to at the same time storeup in a spring the force required to operate such driving pawl, andthereby enable it to actuate the Worm gearing, is derived from themotion of the Whip roller induced by the upward strain of the warpthreads upon the inner bar of the Whip roller at the instant of thebeat.

The accompanying drawings of the let-off mechanism, and so much of theadjacent portions of the loom structure as suffices to illustrate theconstruction and mode of operation of the invention, are as follows:

Figure 1 is a side elevation. Fig. 2 is a horizontal section takenthrough the plane indicated by the line on a: on Fig. 1. Fig. 3 is avertical section taken through the plane indicated by the dotted line yyon Figs. 1 and 2.

The drawings represent the frame, a, of an upright loom for weaving intotwo fabrics, side by side, the warp threads fed froma single warp roll,I), over asingle whip roller, 0, and across and between two systems oflease rods, (1, d, by which the warp threads are divided into four equalgroups, C1, d d (1 as described in pending application Serial No.367,488, filed October 9, 1890, renewal No. 416,915, of January 4, 1892.The shaft or trunnion, c, of the whip roller, 0, has affixed to it thedownwardly-extending radius arm, 6, the lower eX tremity of which isprovided with two laterally-extending ears, 6 and c one of which, c, istransversely perforated to admit of the extension through it of one endof the setting rod, f, the other end of which is pivoted to the radiusarm f, projecting inwardly from the pawl-carrying sleeve F, looselymounted upon the lower end of the vertical worm spindle, G. The sleeve Fis also provided with a radius arm f to which is attached one end of thecontracting spiral spring F, the other end of which is secured to theframe of the loom. The contracting force of the spring f 3 holds theradius arm f against the end of the adjustable horizontal stop bolt, f,extending through a hole tapped transversely through an arm, fprojecting downward and outward from the frame of the loom; the bolt fbeing provided with a jam nut, f, by means of which it may be secured inthe position to which it may have been adjusted. Another radius arm, fprojecting outwardly from the sleeve, F, is provided with an uprightstud to which is pivotally attached a driving pawl, f the free end ofwhich, by means of the spring f is pressed against the periphery of aratchet wheel, g, which is affixed to, or formed in one piece with, thehollow shaft, g, of the worm g engaging the worm wheel, 9 aifixed to thecounter-shaft g", to which there is also aifixed the pinion g, whichmeshes with the teeth of the cog-wheel, g, affixed to the shaft of thewarp roll. At the instant of the beat, the backward sway of the radiusarm, c, carries the ear 6 into collision with the setting rod, f, and byrocking the sleeve F upon its axis, swings back the driving pawl fcausing it to ride over a greater or less number of teeth of the ratchetwheel, g. After the beat has taken place, the radius arm, e, swingsforward, and the sleeve F is thus released to the action of thecontracting spiral spring, f which by its contracting force rocks thesleeve F, and by the engagement of the pawl f with the ratchet wheel 9,imparts motion to the worm 9 which motion continues until the radius armf strikes against the end of the adjustable stop bolt, f By this partialrotation of the worm the desired amount of unwinding motion is impartedto the warp roll. It will be seen that the extent of such motion may bevaried by varying the position of the adjustable stop bolt. Thus, if thestop bolt be unscrewed, the radius arm f will be permitted to swing forward, and the free end of the setting rod, f, will thereby be carriedinto a position in which it will be sooner engaged by the ear e of theradius bar c, so that a larger proportion of the backward swingingmovement of the radius bar, e, will be communicated to the setting barf, with the consequent result that the driving pawl will be drawnbackward over a greater number of teeth .at each loeat. On the Q-hQr-Ahaind, by screwing in thread; astable stop bolt f thetsetting rod,f, will be carried forward, and the collision of its free end with theear 6 will be postponed to a later stage in the backward swingingmovement of the radius bar e, and-a less rangeof setting motion willthereby be communicated to the driving pawl f so that after-the beatfOPlOQIlIS herein described, the same consist I i-ng, essentially,-of =a=worm for imparting. mo-fl tionto the train (if-gearing by iwhichthewarproll is unwound, a ratchet wheel affixed to the ing theteeth-of saidratchet-wheel, spring for forcingsaid-driv-ing pawl forward againsttheratohet toothron which it bears, a-radius arm connectedtothe sleeveof a said pawl, a

stop arranged in, the path ofimotion of said radiusarm for arresting thebackward motionof said driving pawl and thereafter holding th sam:againstthe'foroe ofsaidspring,

.asettin-gbar, for hearing at one-end against the: said radiusarmconnected to said sleeve,

and for receiving; at its opposite end the impact ofaradiusarm a-flixedzto the-shaft of the whip roller for governing the tension of the Warpthreads, and; thereby-trans1nitting motion derived from the beat to setback said driving pawl and store up in said spring force to actuate thelet-off gearing at the conclusion of the beat.

2. A worm shaft, constituting the prime member of a train of gearing forimparting unwindingmotion to the warp roll of a loom,

a ratchet wheel affixed to said shaft, a drivin g pawl carried upon asleeve loosely mountedupon said shaftandadapted.to engage the teeth ofsaid ratchet wheel, a spring'for giving the forward ordrivingmotiontosai'ddriving pawl, a radius arm affixed to the whip-roller shaft, a setting bar; for transmitting at the instant of-thebeat, motion derived from said whip roller toroek said sleeveandtherevby set back said drii" g -paw1,;andooincin y stor sup, insai eping se a lditional ingthestage in the swinging motion of-sa-id radiusarm aftiXed'tosaid-whip roller-shaft at which its motioniscommllnicetedtosaidqset v ,s amount "of:t'or.cefor:reactinga pon said ;driv-' ing-pawl,- inoombi-nationwith ,a movable-stop -for arresting the forwardoraotrmting movement ofsaid driving pawLandtherebyvary- 6o ting bar,:and hencevarying therange 0f ;set- I tingemovcmentimpartedtosaiddrivingpawl, and oonsequently tlieyrange ofauuwindingmotionoommunioatedto the awarpt roll.

ABRAM D. EMERY.

Witnesses;

LI-I. .JJFULLEB,

W. 'TQEMERY.

